CHEN Chaur-tzuhn,CHEN Mei-Kuang.Impact and Adaptation Strategy of Extreme Rainfall on Forest Watershed[J].Research of Soil and Water Conservation,2012,19(01):262-265.
极端降雨对森林集水区之冲击与因应对策
- Title:
- Impact and Adaptation Strategy of Extreme Rainfall on Forest Watershed
- Keywords:
- forest watershed; forest management; extreme rainfall
- 分类号:
- S715
- 摘要:
- 近年来由于全球暖化，极端气候日渐加剧，暴雨所带来的土砂灾害，将破坏森林集水区的地景结构与功能，如何减低或因应极端气候所带来的森林集水区冲击，已是未来集水区经营必须面临的重要课题。该研究以高屏溪集水区为研究范围，以17 a自动测站雨量资料，进行极端降雨趋势分析，并以2001年与2009年桃芝与莫拉克台风所带来的不同降雨量，以卫星影像探讨集水区内不同土地使用分区崩塌比及其变化，以及相对应之降雨量资料，探讨极端降雨与崩塌发生与土地使用分区之关系。研究结果显现2005年以后，高屏溪集水区发生极端气候之频、降雨量与降雨强度有升高趋势。两场不同台风之最大24 h延时降雨量，莫拉克台风为桃芝台风的1.92倍。桃芝台风所造成之崩塌比，自然保护区由灾前的0.64%提升至灾后的0.86%，国土保安区由灾前的0.95%提升至灾后的1.15%，该场台风降雨以地形较为陡峻之自然保护区及国土保安区新增崩塌地比例相对较高，其冲击较为严重，而莫拉克台风则因属超大豪雨（单日累积降雨量达350 mm以上），其降雨范围小且集中，所造成之新增的崩塌范围高出桃芝台风的11.81倍，对于地形相对较为平坦之经济林区，亦造成大量的新增崩塌地，显现超大豪雨级以上的极端降雨，造成林地脆弱，使诱发崩塌之地形条件门槛降低，完整的植生覆盖已无法抵挡极端降雨的冲击，未来林地使用分区经营必须要有新的思维。
- Abstract:
- In recent years, the global warming had increased extreme climate such as heavy rainfall events that had caused sediment disasters and destroyed the landscape structure and ecosystem function. Therefore, how to make operations or strategies for forest management to reduce the impacts of extreme weather events will be an important issue in the future. This research selected the Kao-Ping River watershed as a study site. The rainfall data of 17 years in Kao-Ping River watershed were collected to analyze the pattern of extreme rainfall. We used the remote sensing data to retrieval the landslides distribution caused by different rainfall of Toraji and Morakot typhoon. In addition, the pattern of rainfall would be used to examine the impact and relationship between the landslides and forestland use. The study results show that the frequency of extreme events, rainfall had been increased in Kao-Ping River Basin after the year 2005. The maximum 24 hours rainfall along with typhoon Morakot are 1.92 times than that of Toraji, and the landslides ratio of the Natural Reserve Area during the typhoon Toraji were collapsed from 0.64% to 0.86%, and the National Protective Area were collapsed from 0.95% to 1.15%. The proportion of new landslide of typhoon Morakot was 11.81 times with Typhoon Toraji in Reserve and Protect area due to the steep terrain and heavy rain. Typhoon Morakot also exerted a serious impact on landslides in timber management area and recreation area. The vulnerability of forestland was increased and decreased the induced threshold of landslide. The vegetation cover has been unable to resist the impact of extreme rainfall. The forest division and land use management will have to rethink in future.
参考文献/References:
[1] Fourth Assessment Report of the IPCC. Intergovernmental Panel on Climate Change Impacts, Adaptation, and Vulnerability Climate Change[M]. UK: Cambridge University Press, 2007.
[2] Liu S C, Fu C, Shiu C J, et al. Temperature dependence of global precipitation extremes[J]. Geophysical Research Letters, 2009, 36, L17702, 4 PP.
[3] Bell F G. Geological Hazards: Their Assessment[M].New York: E & F N Spon, 1999.
[4] 汪中和.台湾降雨的长期变化及对环境的冲击[C].台湾:行政院农业委员会林业试验所, 2004.
[5] 周仲岛.台湾地区剧雨与侵台台风变化趋势与辨识研究[M].台湾:气候变迁对灾害防治冲击调适与因应策略整合研究:子计划, 2006.
[6] 林务局.国有林区森林生态系经营计划编订手册[M].台湾:行政院农业委员会, 2001.
[7] 陈财辉.漂流木的处理对策及资源利用[J].台湾林业专讯十月号, 2009, 35 (5):11-15.
备注/Memo
收稿日期:2011-7-18;改回日期:2011-11-6。
基金项目:行政院农业委员会林务局屏东林区管理处委托研究计划系列（99-06-5-03）
作者简介:陈朝圳（1953- ），男，教授，主要研究方向为森林经营、地理资讯系统、资源遥测、森林生态。E-mail：cct@gisfore.npust.edu.tw
通讯作者:陈美光（1980- ），男，硕士，主要研究方向为森林经营、气候变迁、极端降雨等方面的研究。E-mail：billchen3994@yahoo.com